[A_Camera]

I think it is looking more and more like Tesla is aiming to tie automakers to them instead of opening up wide in the US, probably makes sense to have a different strategy compared to the EU since there’s already a big non Tesla network here.

Tesla is for monopoly, and in US they have a strong voice for protecting everything American, no matter if there are any benefits of not from it. That's one major reason for why we still, after all these years, don't have a free trade agreement between the EU and the US. The only reason for Tesla to push this is to protect their own interests, and the only reason why this is possible because of all the lobbyists running around in Washington and the bribed politicians. In my opinion, there are no reasons for "different strategy", definitely not technically. Yes, the charging network is pretty large in EU even without Tesla, but I think it was a good idea that EU forced Tesla to open their network for other cars also. But also, if you would remove all Tesla chargers in EU, we would not have such great network at all in EU. The other thing is that in some parts of Europe, Tesla is still dominating and will do so for some time.

 

[A_Camera]

Well, Geely actually. I mean, they own 82% of Volvo Cars, so... Is that European?

If not, and it is Chinese rather, then maybe this news is all the more impressive.

Volvo is no doubt Chinese... and it's actually a disgrace for Sweden to let it be sold to China. Today it's also severely overpriced and boring. OK, Volvo never been an exciting car, but at least it was Swedish and European when I bought my Volvo cars.

The only Volvo which is still Swedish is Volvo Trucks.

 

[SUNBMR]

There is some confusion around this and a mixture or good and not great information in this thread.

SAE and CharIN are both trying to start the process of turning NACS into an actual open standard, but Tesla so far has not announced participation or allowance of either of these processes. Without their blessing, it cannot happen. NACS is, as of today, still Tesla's IP. It cannot be turned into an open standard unless they allow it to.

Second, if they don't turn it into an open standard, there are a lot of things they could do to cause a ton of problems in the industry besides just shutting off access to the Supercharger network (and turning NACS into an open standard won't stop that either.)

The main issue is that unless it is an open standard, Tesla can change it at any point. Keep in mind, as has been stated many times, NACS is only the spec of the physical plug and socket, not the communication protocol that is used between the car and charger. But even so, if Tesla retains control of NACS, they could change the spec in a way that makes some other manufacturer's implementation incompatible. Or they could say "Hey we are updating it for Megawatt capability and here is how we are doing it." And maybe their way is a way that works for them but is something other manufacturers are uncomfortable with due to safety concerns or something.

Basically, if Tesla retains control, other manufacturers (not only cars, but chargers too) have no guarantee of a seat at the table for the future. If it gets turned into an open standard (whether by SAE or CharIN or someone else like ISO) then members of that org can have more involvement in changes down the road.

Of course, one might argue that Tesla's unilateral control has something to do with why NACS is so much better to use than CCS....

 

[gsbaker]

There is some confusion around this and a mixture or good and not great information in this thread.

SAE and CharIN are both trying to start the process of turning NACS into an actual open standard, but Tesla so far has not announced participation or allowance of either of these processes. Without their blessing, it cannot happen. NACS is, as of today, still Tesla's IP. It cannot be turned into an open standard unless they allow it to.

Second, if they don't turn it into an open standard, there are a lot of things they could do to cause a ton of problems in the industry besides just shutting off access to the Supercharger network (and turning NACS into an open standard won't stop that either.)

The main issue is that unless it is an open standard, Tesla can change it at any point. Keep in mind, as has been stated many times, NACS is only the spec of the physical plug and socket, not the communication protocol that is used between the car and charger. But even so, if Tesla retains control of NACS, they could change the spec in a way that makes some other manufacturer's implementation incompatible. Or they could say "Hey we are updating it for Megawatt capability and here is how we are doing it." And maybe their way is a way that works for them but is something other manufacturers are uncomfortable with due to safety concerns or something.

Basically, if Tesla retains control, other manufacturers (not only cars, but chargers too) have no guarantee of a seat at the table for the future. If it gets turned into an open standard (whether by SAE or CharIN or someone else like ISO) then members of that org can have more involvement in changes down the road.

Of course, one might argue that Tesla's unilateral control has something to do with why NACS is so much better to use than CCS....

It looks like you sense the sweet with the bitter.

But why should tesla want to do harm and risk anti-trust action when they can win big by doing good?

Be patient.

 

[Jonathan S.]

[...] But why should tesla want to do harm and risk anti-trust action when they can win big by doing good?

Be patient.

Agreed!

And regarding Tesla's possible motives -- other than the obvious incentive of increasing Supercharger revenue via CCS access -- one overlooked development is that starting in 2020, Tesla has been equipping its vehicles with the ability to charge at CCS DCFC via a nearly free adapter.
If Tesla has some sort of long-term plot to eliminate alternatives to its own Supercharger network even for CCS EVs, then it goes against eliminating its previous DCFC monopoly for its own vehicles.

 

[SUNBMR]

It looks like you sense the sweet with the bitter.

But why should tesla want to do harm and risk anti-trust action when they can win big by doing good?

Be patient.

the main thing for me is Elon is unpredictable. He doesn't act rationally. If he leaves Tesla I'd say the risk or them doing anything crazy is near zero. With him calling the shots.... i can understand why manufacturers might want guarantees.

 

[trivalent]

But why should tesla want to do harm and risk anti-trust action when they can win big by doing good?

Be patient.

the main thing for me is Elon is unpredictable. He doesn't act rationally. If he leaves Tesla I'd say the risk or them doing anything crazy is near zero. With him calling the shots.... i can understand why manufacturers might want guarantees.

Correct. Because 12-year-old child is why.

Although I never raised children, I have seen them in action and once was one myself. In this domain, I will neither be patient nor trust my fortunes to the whims of a child.

 

[SpiritAdriftM]

No need to do that. They have their magic plugs that can satisfy both systems. They just need to install half as magic plugs and they receive full funding.

Yet they can serve 100% nacs when needed.

Nice play for them.

Federally, yes. Texas and Kentucky and maybe others require one of each.

 

[KarlInSanDiego]

The following is an excerpt from a contracting company eager to help engineer solutions for manufacturers. They are not discussing plugging a BMW with CCS into a NACS home charger, though that is distinct possibility if adapters become the norm for everyone to undergo a quick transition. New home EVSE's with J1772 plugs could go extinct in the coming years as the old tech is quickly abandoned. The better way to read the following is just to realize that Tesla in their own ecosystem, designed their plug to do this with their cars, their home chargers and their DC superchargers.

How did Tesla achieve the compact design of NACS?
They did this by sharing the AC and DC pins. This, however, creates complexity to the point that the highest safety rating (ASIL D) is applied to the hazard of connecting a 400V DC battery to a grid that can be as low as 120V AC. Complexity in Tesla NACS could be a bottleneck for its mass adoption. The interface between the charging station and the electric vehicle via NACS takes a variety of components and systems that work together to provide fast and reliable charging for electric vehicles. If this was to happen, your toaster oven will likely catch fire.
So how to we mitigate this hazard?
The hazard of energizing your home power grid with 400V DC will cause appliances to burn and is unique to NACS. Tesla uses a sophisticated Battery Management System (BMS) with smart charge port door controls and other vehicle software which has the appropriate hardware redundancy. Because quite a few BMSs and vehicle controllers are not easily modifiable, this isn’t a good option for some OEMs due to the complexities of re-validate a critical safety system. For those OEMs who have the capability of vertically integrating, or working with high-tech Tier 1 suppliers, NACS gives OEMs an advantage to the number one charging network.
-quote from

NACS vs. CCS: A Comprehensive Comparison

Understand what to choose between Tesla NACS and CCS to help you opt for the one that fits best according to your needs.

www.amp.tech

https://en.wikipedia.org/wiki/Automotive_Safety_Integrity_Level

So in essence what this is saying is that the CHAdeMO, GB/T, CCS1 and CCS2 plug designs intentionally kept the high voltage DC cabling completely isolated from the AC cabling. It was a wise engineering choice, because a failure in the charge switching in the vehicle, can lead to an unintended interconnection of a home's AC 120V system (and the grid) with a DC 400V (or 800-900V in the case of Porsche, Kia, Hyundai, Genesis, Lucid, GM?). Tesla said, hold my beer. We can make sure that the car's charge controller knows how to switch those cables and what could possibly go wrong? You saw me launch a Roadster into space. Trust me. Is Tesla UL listed? Are any of these cars? What's the worst that can actually happen when a charge controller's switching or the BMS fails on an EV?

This page in the NACS "spec" shows a block diagram of how the switching can be handled within the car. It's on page 5 and contactors are K3 & K4.

https://tesla-cdn.thron.com/static/HXVNIC_North_American_Charging_Standard_Technical_Specification_TS-0023666_HFTPKZ.pdf?xseo=&response-content-disposition=inline%3Bfilename%3D%22North-American-Charging-Standard-Technical-Specification-TS-0023666.pdf%22

 

[Klaus-rf]

The hazard of energizing your home power grid with 400V DC will cause appliances to burn and is unique to NACS.

Totally impossible. Exactly ZERO Tesla's have VtG/VtH capability so the battery voltage is NEVER directly available on the charge port connector.

So in essence what this is saying is that the CHAdeMO, GB/T, CCS1 and CCS2 plug designs intentionally kept the high voltage DC cabling completely isolated from the AC cabling.

Not accurate for CCS. There are three data / control pins, two shared AC and DC low power pins (<50KW DC) and two high power DC pins (>50KW). So for low power DCFC, the same pins that are used for [low power] AC are also used (shared).

Essentially what these posts / articles ar saying is that ANY EV plugging into your home electrical system via EVSE to charge COULD back-feed 400+VDC into the house.

AFAIK that has never happened.

 

[SUNBMR]

The following is an excerpt from a contracting company eager to help engineer solutions for manufacturers. They are not discussing plugging a BMW with CCS into a NACS home charger, though that is distinct possibility if adapters become the norm for everyone to undergo a quick transition. New home EVSE's with J1772 plugs could go extinct in the coming years as the old tech is quickly abandoned. The better way to read the following is just to realize that Tesla in their own ecosystem, designed their plug to do this with their cars, their home chargers and their DC superchargers.

How did Tesla achieve the compact design of NACS?
They did this by sharing the AC and DC pins. This, however, creates complexity to the point that the highest safety rating (ASIL D) is applied to the hazard of connecting a 400V DC battery to a grid that can be as low as 120V AC. Complexity in Tesla NACS could be a bottleneck for its mass adoption. The interface between the charging station and the electric vehicle via NACS takes a variety of components and systems that work together to provide fast and reliable charging for electric vehicles. If this was to happen, your toaster oven will likely catch fire.
So how to we mitigate this hazard?
The hazard of energizing your home power grid with 400V DC will cause appliances to burn and is unique to NACS. Tesla uses a sophisticated Battery Management System (BMS) with smart charge port door controls and other vehicle software which has the appropriate hardware redundancy. Because quite a few BMSs and vehicle controllers are not easily modifiable, this isn’t a good option for some OEMs due to the complexities of re-validate a critical safety system. For those OEMs who have the capability of vertically integrating, or working with high-tech Tier 1 suppliers, NACS gives OEMs an advantage to the number one charging network.
-quote from

NACS vs. CCS: A Comprehensive Comparison

Understand what to choose between Tesla NACS and CCS to help you opt for the one that fits best according to your needs.

www.amp.tech

https://en.wikipedia.org/wiki/Automotive_Safety_Integrity_Level

So in essence what this is saying is that the CHAdeMO, GB/T, CCS1 and CCS2 plug designs intentionally kept the high voltage DC cabling completely isolated from the AC cabling. It was a wise engineering choice, because a failure in the charge switching in the vehicle, can lead to an unintended interconnection of a home's AC 120V system (and the grid) with a DC 400V (or 800-900V in the case of Porsche, Kia, Hyundai, Genesis, Lucid, GM?). Tesla said, hold my beer. We can make sure that the car's charge controller knows how to switch those cables and what could possibly go wrong? You saw me launch a Roadster into space. Trust me. Is Tesla UL listed? Are any of these cars? What's the worst that can actually happen when a charge controller's switching or the BMS fails on an EV?

This page in the NACS "spec" shows a block diagram of how the switching can be handled within the car. It's on page 5 and contactors are K3 & K4.

https://tesla-cdn.thron.com/static/HXVNIC_North_American_Charging_Standard_Technical_Specification_TS-0023666_HFTPKZ.pdf?xseo=&response-content-disposition=inline%3Bfilename%3D%22North-American-Charging-Standard-Technical-Specification-TS-0023666.pdf%22

this is fear mongering. I mean the facts of what would happen if you wired the battery directly to your house circuit are accurate, but Tesla is no longer a new company. People have been home charging Teslas for over a decade. They have sold millions of cars. I'm not aware of this scenario ever happening. So i don't think it's reasonable to try to scare people about it with this.

 

[KarlInSanDiego]

Totally impossible. Exactly ZERO Tesla's have VtG/VtH capability so the battery voltage is NEVER directly available on the charge port connector.



Not accurate for CCS. There are three data / control pins, two shared AC and DC low power pins (<50KW DC) and two high power DC pins (>50KW). So for low power DCFC, the same pins that are used for [low power] AC are also used (shared).

Essentially what these posts / articles ar saying is that ANY EV plugging into your home electrical system via EVSE to charge COULD back-feed 400+VDC into the house.

AFAIK that has never happened.

Are you sure that low power DC charging via the top portion on the J1772 connector was ever implemented? AFAIK, we only saw DC charging on cars in North America after the CCS standard was created and the plug was extended to include stand alone DC pins. Was that DC low power option in the J1772 standard pre or post 2017? This is the first time I've seen a reference to shared use of the AC pins for DC.

 

[KarlInSanDiego]

Not accurate for CCS. There are three data / control pins, two shared AC and DC low power pins (<50KW DC) and two high power DC pins (>50KW). So for low power DCFC, the same pins that are used for [low power] AC are also used (shared).

You're assuming that manufacturers didn't choose to use "DC Level 2" charge procedure for any and all DC applications. The standard doesn't preclude you from using DC Level 2 for below 80kW charging. But there is an upper limit of 80kW for DC Level 1. It's an optional implementation to support "DC Level 1" as a part of the standard.

 

[KarlInSanDiego]

Totally impossible. Exactly ZERO Tesla's have VtG/VtH capability so the battery voltage is NEVER directly available on the charge port connector.

You might be mixing up intended or experienced operation with potential operation when a component like a contactor eventually fails. These parts are not forever. They fail.
Here is a test that NHTSA recommended in 2019 for manufacturers to prepare for the worst
"Reverse Power Flow (Under-Voltage) Test (DC Only) - Unintended discharge of the RESS (i.e., not V2G functionality) could possibly degrade/damage the RESS." - page 118

Under DC charging, the Charge provider is pushing DC current directly to the the pack with the BMS monitoring things. The direction of current flow is dependent on the Charge provider holding a higher voltage than the BMS/pack has. If the Charge provider under DC operation falls below the pack voltage, reverse power flow would occur. So they have failsafes to account for that, like contactors in the EV breaking the circuit.

Now imagine a communication session going haywire, and an EV believing it's in DC charging mode, while a garage based EVSE believes it's in AC charging mode, trying to push 240V AC into the car via the NACS L1 L2 lines. The EVSE is essentially acting like a 240v power cable at that point, with direct circuit to your breaker box, your home, and the grid. But because the car got confused about being in DC mode, it applies 400v DC to the charge cable which is the scenario that I highlighted in red above. With the benefit of hardware contactors that function properly the circuit is quickly broken. This is why they didn't say what NACS does is impossible. Clearly it's possible. It's just a hightened cause for more safety precautions because of the mixed use of AC and DC (both using high power ranges and different voltages) using the same pins and a shared circuit intended for different destinations (on-board EV charger vs. pack) in different operating modes.

With J1772 (and CCS), the car charge port AC lines are connected to the on-board charger, not the EV's pack.

 

[SUNBMR]

You might be mixing up intended or experienced operation with potential operation when a component like a contactor eventually fails. These parts are not forever. They fail.
Here is a test that NHTSA recommended in 2019 for manufacturers to prepare for the worst
"Reverse Power Flow (Under-Voltage) Test (DC Only) - Unintended discharge of the RESS (i.e., not V2G functionality) could possibly degrade/damage the RESS." - page 118

Under DC charging, the Charge provider is pushing DC current directly to the the pack with the BMS monitoring things. The direction of current flow is dependent on the Charge provider holding a higher voltage than the BMS/pack has. If the Charge provider under DC operation falls below the pack voltage, reverse power flow would occur. So they have failsafes to account for that, like contactors in the EV breaking the circuit.

Now imagine a communication session going haywire, and an EV believing it's in DC charging mode, while a garage based EVSE believes it's in AC charging mode, trying to push 240V AC into the car via the NACS L1 L2 lines. The EVSE is essentially acting like a 240v power cable at that point, with direct circuit to your breaker box, your home, and the grid. But because the car got confused about being in DC mode, it applies 400v DC to the charge cable which is the scenario that I highlighted in red above. With the benefit of hardware contactors that function properly the circuit is quickly broken. This is why they didn't say what NACS does is impossible. Clearly it's possible. It's just a hightened cause for more safety precautions because of the mixed use of AC and DC (both using high power ranges and different voltages) using the same pins and a shared circuit intended for different destinations (on-board EV charger vs. pack) in different operating modes.

With J1772 (and CCS), the car charge port AC lines are connected to the on-board charger, not the EV's pack.

yes and how many times has this happened with the literally millions of Teslas charging every day for the past decade?

i'd say they engineered around this. There's a lot of bad things that "could" happen if the stars align. If your car fails to disconnect the traction battery and engage the parking brake and the accellerator switch fails too then the car could drive through your house as well. But that's what safety engineering is for.

 

[awmyvr]

Question is, why would Tesla want this? NA is the biggest market for personal vehicles and non Teslas are on the backfoot when it comes to roadtrip charging. If Tesla is in the business of selling cars, then I don't see a reason for them to open up their SC to competitors other than doing the bare minimum to collect subsidies. If Tesla is pivoting to be the "gas station of EVs" then they can simply provide an adapter today and let any EV plug in to their SCs. Either way, this mostly doesn't look like BMW's decision to make as their home market Europe surely isn't going to adopt NACS ever.

With a NACS standard, Tesla can sell power to all EV’s and Tesla owners get an even larger charger network, thats why this makes sense.

 

[KarlInSanDiego]

Google contactor failure, contactor welding, and know that one set of contactors are sealed in the Tesla pack. My bachelor's degree is in electrical engineering. I'm not afraid of electricity, and I'm not trying to spook anybody that they're going to burn their house down. I'm pointing out that they made a questionable choice when being clever with their cabling choice and the dual usage of AC and DC on the same interface.

Here's a block of text from page that also warns about all the dangers of sharing AC and DC pins in EVs: Prize goes to the first person who can identify who published this "fear mongering" information and what the name of the report is.

"A hazards and risks assessment can be used to derive the ASIL level of the failure mode and primary safety goal:

Function: Don’t connect HV battery to an AC electrical grid

Malfunction: System allows HV battery to be connected to an AC electrical grid

Worst-Case Scenario: Stationary vehicle charging

Hazardous Effect: Damage to grid-connected devices and possible thermal event

Safety Hazard: Severe failure of grid-connected devices, thermal event

Reliability Hazard: Damage to vehicle components rendering the vehicle inoperable

Exposure Rating: E4: >10% of average vehicle operating time

Severity Rating: S3: Life threatening or fatal injuries

Controllability Rating: C3: No action can be taken by user once failure has occurred

Reliability Rating: R3: Permanent damage to vehicle

The above ratings are used to derive a safety criticality level of SCL2(D) and reliability criticality level of R3. This gives the resulting safety goal (avoid connecting the battery pack to an AC electrical grid) an ASIL rating of ASIL-D."

 

[Jonathan S.]

With a NACS standard, Tesla can sell power to all EV’s and Tesla owners get an even larger charger network, thats why this makes sense.

Tesla owners already have access to all CCS DCFC.
Only about $100 for an aftermarket adapter for Tesla vehicles from 2020 on, or a $450 retrofit (including the adapter) for earlier Teslas.

 

[awmyvr]

Correct, though native connectivity is superior, no “dongles” fewer things to go wrong/break.

 

[Sparky]

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Mercedes-Benz is on board with NACS too now. Even with building their own MB charging network.

IMHO, this announcement means it's now inevitable that BMW will transition to NACS in NA too. Even removing "customer satisfaction" out of the equation, there's no way BMW can ignore NACS when their chief rival is doing it.